mannesmann



(ModeL) 2 Sheets-Sheet 1. V M. MANNESMANN.

' MANUFACTURE OF SEAMLESS TUBES. v

K013613254. t Patented Apr. 26,1887.

Model.) 3 Sheets-Sheet 2.

M. MANNESMANN. MANUFACTURE OF sBAI LBss TUBES.

NO. 361,954. Ratented Apr. 26, 1887.

I fifimswx \WK MLMM J M maw "il'm'rnn STATES P TENT OFFICE.

MAX MANNESMAHN, OF REMSGHEID, GERMANY.

MANUFACTURE OF ssAMLsss Tunas,

EPlhfifi-HGATION forming part of Letters latent No, 361.95%, dated April 26, 1887.

lrdicn iion filedFol-rnm'y 25, 1857. Serial No. 229,057. (Modcl) Patented in Belgium August 14, 1886. No. 54.857, am: in

- France August 19, 1856, No. 165,290.

n32 whom itmay concern:

be it known that I, -.lllsx MANNESMANN, of P/cmscheid, Germany, have invented certain Improvements in thelll'anufacture of Seamless 5 Tubing, of which lien.

This invention relates to a. modification in thc process of forming tubes i'rom solid metnlllo ingots or blanks by the use of diagonallyr0 acting-rolls, between'thc converging working laces cf which such ingots have been passed @Eltl'li'lfifi- The invention is based upon the discovery that by a suitable proportioning of the angles .15 of obliquity of the diagonally-acting rolls and the length and anglesof convergence of. their working-faces they will operate to develop a tubular formation in any part of a solid me.-

.tnllic ingot or blank which is submitted to their action by causing a rupturing of the metal along the line of the geometric axis of such port and a radiallyoutward displacement of the metal therefrom,

blank of metal may ransformed into a tube without the use of mandrel. for bearing against and holding the central portion of the blank, or {or in the development of the tubular ration. "e proportioniug and adjustment of the nregovcrned by the degree of softness and lity of the metal which is to be operated npon hence a different proportioning and adjustment oi the rolls will be required for the different metals, or even for the some metals {it diiierent heats.

It is be observed that in the operation of diagonsllg rolling a. metallic. blank theblank is reduced in diameter by the convergence of c the working-laces of the rolls or rolling dies, in passing between which it is subjected to an cudwise stretching, which is greater or less according as the direction in which the rolls act more or less oblique. The blank is also caused to rotate by reason of the opposite directions in which the dies act upon opposite sides of it.

Although not in all cases necessary, it isdesirable, especially in the manufacture of iron 50' and steel tubes, that the portion of the blank on which the dies act shall haveimparted to the following is a; specifica-l and hence that the it a progreasively-increasingspeed of rotation, so that the fibers of the metal will be madoto extend spirally around the axis of the blank. Strong twist is given to the fibers for two purp0ses-to wit, to render the interior surface of the tube formed by the action of the rolls less rough and irregular, and to give the tube greater capacity to resistiutcrual pressure. The desired twist is most efiectuallyimparted to the fibers by the employment of dies of such shape and arrangement that the diameters of the working-faces of the dies increase with greater or less rapidity from the place where they first engage the blank to the place where they effect the greatest reduction in the diameter of the blank. To enhance the effectiveuess of the dies in imparting this increasing twist to the metal operated upon, the workingfaces of the dies are provided with projecting ribs, or are otherwise so corrugated or roughcued as to enable them to take a more elfective hold upon the metal along the line oftheir impingement upon the blank, and thereby to move-such metal in a spiral direction.

The desired rupturing efiect and radial dis- 1 placement of the metal from the center of the blank are most easily efi'ected by the employment of two rolls or rolling dies, which act, respectively, upon diametrically opposite sides of the blank. In passing betwecntwo dies the metal compressed in one direction by the squeezing action of the dies tends to expand in directions which are lateral to the liueof compression, and as the blank revolves the directions with relation to the blank of the planes of compression and "expansion are constantly changing. Therefore in adjusting and proportioniug the rolls the angles of convergence of their workingi'aces must be such as to produce a suitably-moderate reduction in the diameter of the blank, and the obliquity of the direction in which the rolls act must be such that the stretching effector the longitudinal movement imparted to the blank, while not being too great nor too rapid to afford time for a sufiicient number of rotations of the blank to bring about the central rupturing effect, will be commensurate with the tendency of the portion of the blank which is being operated upon to elongate itself while it is assuming the tubular form and the fibers are 2 a eeissc acquiring their spiral positions in the shell of the tube. This can be more conveniently describedin corinection with the accompanying drawings and diagrams. which are as follows:

5 Figures 1, 2, 3, 4, 5, andfirepresentin central longitudinal section a solid metallic ingot or blank at difi'erent stages in its transformation into a tube during its endwise progress between two conical rolls, the axes of which are to oppositely inclined from the horizontal path through whichuhe tube travels. Fig. 7 is a side elevation of the rolls, showing the blank in process of transformation into a tube. Fig. 8 is a diagram of the blank and rolls in trans- I 5 verse section, indicating, theoretically, the effects of compression upon the metal and the direction in which the forces of compression are propagated from the places where the rolls impinge, respectively, upon the opposite sides of the blank. Fig. 9 illustrates the eiiect of tensile stress in reducing the diameter of a uniformly ductile solid metallic bar. Fig. 10 illustrates the theoretical effect of tensile stress upon a metallic bar the center of which is 2 5 ruptured and the outer portion of which has been hardened, by compression, and thusrendered less'soft and ductile-thanfthe interior portion. bar or blank which has'been circumferentially 3o grooved in the middle and chamfered at its ends; and Fig. 12 is a longitudinal section'of the product resulting from the subjection of the form of blank shown in Fig. 11tothe ac tion of the diagonal rolls, and in which, as will be seen, the middle and end portions are solid and the portions intervening between the solid middle and ends are tubular.

For convenience of description itwill be as".

sumed that the two rolls shown in Fig. 1 and 0 the other corresponding figures-are arranged,

respectively, on either side oi a horizontal path through which the blank travels; that the vertical planes of the axes'oi these rolls are parallel, and that their axes respectively are oppositely inclined from the horizontal plane of the path through'which theblauk travels. It is also assumed that the conical portion of the side of each roll is at an angle of five degrees with its axis, and'that the axial length of the'cylindrical portion of each roll is two and five-tenths inches and the axial length of .in its passage between the diagonally-acting rolls are oi; complex character.

the remainder or conical portion of each 'roll is five inches; it is assumedthat the rolls are adjusted for operating upon a cast steel blank which has hegiiheated to a bright red heat, and that the original diameter of the blank is fifty millimeters, and that in passing endwise through the rolls its external diameter is di minished to thirtymillimeter's; hence that there is a space of thirty millimeters between the cylindrical portionsof the rolls where they most nearly approach each other.

In Fig. 1 the rolls are represented as having their working-faces provided with spiral corrugations. They may be otherwise corrugated or roughened in any way to prevent their slipping and to give then; a more eiiective hold Fig. 11 is a side View of ametallic,

upon the metal of the blank against which. they impinge, whereby the displaced metal will bemade to flow more ncf'tily'in the direc- 7e tions in which the rolls act. The corrugation or roughening of their surfaces improves the adaptability of the rolls to operate upon iron or steel blanks, and especially their capacity to impart the strong twist to the fibers of the metal which carries the fibers spirally around theshell of the tube formed by the action of the rolls and thereby makes the interior surface cf the tribe smoother and the shell of the tube stronger. do

In operating upon metals which are softer or more ductile than iron or steel, rolls having smooth working-faces may be employed.

The rolls A to rotate in the same direction, as indicated by the arrows A a, and impart rotation in the opposite direction to the blank B, against the opposite sides of which the working-faces A a of the rolls respectively impinge. p a

For operating by means of rolls of the dc.- en scribed dimensions the working-faces oi'which are arranged to have the. described angles of convergence,-the axes of the rolls require to have inclinations of from 1.8 to three degreesfrom the horizontal plane in opposite g5 directions, accordingly as'the metal operated upon is more or less hard. Suchinclinations are indicated approximately iuFig. l. and in the similar figures by the views which. they each afford of the larger end, A, of the roll A.. ioo and of the smaller end, a, of the roli'a.

The drawings are not made to scale, but the described dimensions are given for the purpose of illustrating an example of proportion and adjustment of the rolls which is suitable r05 forefiectingthe transformation of a blank oi cast-steel fifty millimeters in diameter into a tube of thirty millimeters external diameter.

,No attempt is made to represent the gearing bywhichthc rolls are driven, nor any organ" 1 I0 ized machine in which they'5'are placed, nor

any supports or guides "for supporting and guiding the blank, because the machine forms no part of ,the present invention, and because diagonal rolling machines provided with I i5 guides forthcobject operated upouere already known. I

The forces to whichthe blank is subjected act upon opposite sides of the blank with a.v

kneading eifect, com pressing the metal against 3 which they impinge to a certain depth beneath the'suri'ace. The cross area-ofthe metal thus compressed isindicated approximately by the i545 sect-ionlined triangles C Q, shown in Fig. 8,

which is a diagram of the blank in cross-section, representing the rolls arranged one above and the other beneath the blank. I The direction in which the forces of compression are propagated from the-places where the rolls impinge upon the blank. is indicated by the arrows which diverge from the section,-

liucd triangles C 0, respectively. It will be The two rolls 1 2o seen that mg outwardly from of course revolving in the opposite direction,

ell pnrtsei its circumference are in succession subjected to-the knee-ding cffectof the rolls, and thus the entire exterior of the black is compressed and thereby hardened to a certain depth beneath the surf-nee, and all parts of the interior of the blank are successively brought into the position, in which they acquire the tendency to expand in the directions indicated by the screws 0 G. The final efiect of this tendency is to cause a ruptnring'of the blank along the line of its geometrical axis and the radislly-outward noveihent of the metal therefrom. There is, however, another influence exerted upon the blank which assists in imparting to it the tendency to become hollow. This is the longitudinal stretching efiect to which it is subjected by the rotation of the converging diagonally-acting rolls.

lo. Fig. lljhe familiar eiifect oftensile stress upon ssolid metallic bar, E, is represented by the reduced diameter of the central portion, e. In this case the metal is assumed to be uniformly soft and ductile throughout its entire moss and the fibers are assumed to have their ordinary adherence to each other.

Fig. 10 exhibizs theoretically the effect of tensile stress upon'a bar of metal the fibers of which have been separated by a rupture extending along the line of the geometrical axis of the bar, and the exterior shell of which has been compressed and hardened to a certain depth, while the interior portion retains the degree 01 softness which i t original] y possessed. In this case, as will be seen, the diminution in solid cross area of the central portion of the bar F resulting from the tensile stress exerted upon it is due to the development of the envityf in the interior of the bar. Fig. 10 may be regarded as ounpproximote representation oi s bar the exterior portion of which has been compressed find hardened and the interior poo tiou ruptured by the action upon it of the diagonal rolls.

The grcntcsli hollowiug ellcct is produced I when two rolls are employed, and when they not, respectively, on diametrically opposite sides of the blank, as illustrated in Fig. 8; but if, for any rcnson,it is desired to produce in the interior of the blank :1 hole of small diameter, the two rolls may be so arranged as not to not on dicmetricully-opposite sides of the blank, or three. rolls maybe employed instead of two, in eiihcr of which cases the tendency of the hlzuil: to expundluterolly induced by the compressive fol-cc olcitlicr oncofthe rolls will be to u greater or less extent counterbalanced by the compressive force exerted by one or both of the other rolls.

In general, 1' t is to be observed that the tendency of the solid blank to acquire the shape of a. tube, and the inner diameter of the resulting tubularibrmsiiomdependmmong other things, upon the position of the blank between the two or three rolls which maybe employei'and that the more nearly diametically opposite the compressive forces exerted upon the blank the greater will be the tendency of the blank to acquire ahollow form; i

From what has been said it will be perceived that the angles of obliquity at which the di agonul rolls act and the angles of convergence nud progressive variations in diameter of their working-fuces must be relatively so proportioned oriadjusted us to importto the portion of the blank which isbeingoperoted open, during the time while it is being reduced from its original to itsficul diameter, a suificicnt number of revolutions to enable the rolls by their knesdi'ngact-ion to effect the central rupturing of the blank, and by their progressive variability in diameter to impart the desired spiral twist to the reduced port of the blank, and by their oblique action to exert the desired stretching effect, or, in other words, to import the necessary longitudinal movement to the blank.

There are two ways of diminishing thenunr ber of revolutions imported to the blank while it is being reduced in diameter during its passage between the rolls. One is by making the convergence of the working-faces of the reducing-rolls more abrupt, and the other is by increasing the angles of obliquity a l; which the rolls act without changing the angles of convergence of their working-faces; and, similarly, there are two ways of increasing the number of revolutions of the blank-either by making the workinglnccs of the rolls less abruptl y convergent or by changing the angles of obliquity at which the rolls act in such a way as to maize them more nearly perpendiculor to the axis of the blank; and it will of course be seen that the two methods of changing the number of revolutions imparted to the blnnl -which consist of altering the angles of convergence of the working-faces of the rolls or of altering the angles ofobliquity at which the rolls act- 1:19.3, be employed. either separately or together, as may be desired.

Variations in adjustment in the respects indicated will be required when there is a change in the amount of reduction in external diametcr to which the blank is to be subjected, and also when it is desired to effect a change in the interior diameter of the tubular formation. Thus, if it be desired to increase the internal diameter of the tubular formation, the axes of the rolls will be so adjusted as to r ndcr the directions of their action more u only perpendicular to the axis of the blanks, in which cuss while the reduction in the diameter of the blank is inking place the porlieu of the blank acted upon will have imported to it a greater number of rcvoluiions,

which will make the pitch of the spirally-laid fibers finer and diminish the thickness of the shell of the tube.

Vhat is claimed as the invention is- V 1. The improvement in the art of transforming it seijhl metallic blank into minnow hotly or tube, which consists in passing the blank endwise between theworkingfaces of diagonally-acting rollsiso proportioned and adjusted as to progressively reduce the diam eterof the blank to a prescribed extent while imparting to it a prescribed number of rotations,whereby the blank is prognessivelyrnptured along the line of its zilxis and an ontwtu'd inoyenient of the metal from the center" of the blank is concurrently induced.

2. The improvement in the art. of transforminga solid metallic blank into a seamless tube and rendering the interior surface of such tube comparatively smooth, which consistsin progressively reducing the diameter 5r the blank, rupturing it along the lineof its axis. and imparting to the portion of the blank; acted upon a progressiyely-varying speed of rotation l by means of stfitablypro ortioned and adjusting dingonnlly actingW l'nfffig' 'rolls-irnpiuging upon different sides of the blank, substantiall y as herein eel-forth;

3. The product obtained by the method herein described as a new article of malnufae tu re, the same consisting, essentiell y, ofa rolled seamless t-nbe constituted of a single integral bar of metal, thetfibersvof which arecontinu: V

ANNIE M. JONES, M. L. ADAMS. 

